title: Identification and evaluation of cyp1a transcript expression in fish as molecular biomarker for petroleum contamination in tropical fresh water ecosystems.
abstract: In order to monitor potential contamination deriving from exploration and transport of oil in the Urucu region (Brazil), there is a need to establish suitable biomarkers for native Amazonian fish. Therefore, the transcript expression of various potentially sensitive genes (ahr2(1), cyp1a, hmox1, hsp70, maft, mt, nfe212, gstp1 and nqo1) in fish exposed to water soluble fractions of oil (WSF) was compared. The analysis was first performed in an established laboratory model, the zebrafish embryo. The cyp1a gene proved to be the most sensitive and robust marker for oil contamination and, hence, was selected to study the effect of oil-derived contaminants in the Amazonian cichlid Astronotus ocellatus. Induction of cyp1a transcript expression was observed for ≥0.0061% (v/v) WSFs. In liver samples of fish, collected from different lakes in the Urucu oil mining area, no elevated expression of cyp1a transcripts was observed. The data demonstrate the high sensitivity of cyp1a as indicator of oil exposure; further studies should be considered to test its usefulness at known contaminated sites and to evaluate influential factors by, e.g. mesocosm experiments.
authors.affiliation: Laboratory of Ecophysiology and Molecular Evolution, National Institute for Research in the Amazon (INPA) Ave André Araújo 2936, 69060-001 Manaus, AM, Brazil.
authors.forename: Nislanha Ana
authors.initials: NA
authors.lastname: dos Anjos
authors.forename: Tobias
authors.initials: T
authors.lastname: Schulze
authors.forename: Werner
authors.initials: W
authors.lastname: Brack
authors.forename: Adalberto Luis
authors.initials: AL
authors.lastname: Val
authors.forename: Kristin
authors.initials: K
authors.lastname: Schirmer
authors.forename: Stefan
authors.initials: S
authors.lastname: Scholz
mesh_terms: D000818:Animals; D015415:Biomarkers / Q000378:metabolism; D001711:Biotransformation; D055884:Chemical Hazard Release; D023681:Cichlids / Q000235:genetics* / Q000378:metabolism; D019363:Cytochrome P-450 CYP1A1 / Q000235:genetics* / Q000378:metabolism; D017753:Ecosystem; D004625:Embryo, Nonmammalian / Q000187:drug effects / Q000378:metabolism; D029941:Fish Proteins / Q000235:genetics / Q000378:metabolism; D005618:Fresh Water / Q000737:chemistry; D015870:Gene Expression / Q000187:drug effects*; D006841:Hydrocarbons, Aromatic / Q000032:analysis / Q000378:metabolism / Q000633:toxicity; D010578:Petroleum / Q000032:analysis / Q000378:metabolism / Q000633:toxicity*; D014329:Tropical Climate; D014874:Water Pollutants, Chemical / Q000032:analysis / Q000378:metabolism / Q000633:toxicity*
chemical_list: D015415:Biomarkers; D029941:Fish Proteins; D006841:Hydrocarbons, Aromatic; D010578:Petroleum; D014874:Water Pollutants, Chemical; D019363:Cytochrome P-450 CYP1A1